SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cc90a205689be8dff0ac64dba43a326d202823da104b2a88f9ab26ec0377b05' 
  AND token = 'rfqbvzjez5iXg9q/uOerNkEwe0irSYfe8QysHFBxe18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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