SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ef1a9c01a514c6ee60b1b7886cce213af60ef6fdaf5e2441306384b4f125ddd' 
  AND token = '+K+RCmiM4X/vtEYVUfm1Ick319O+RFB2z4MrwD+SW98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}