SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e0b6c9683f26941d01ed4aa57cbd149eaec6a6469bf480b91fe7c11e5a8ebfd' 
  AND token = 'uIXY38na5E42Z0AXLGNPPUago/b5tUTjADnC/fZVTF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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