SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a78604ea18e468e3217337c0035c4968a1605f63c59d96b30cc7c40f9eb184ef' 
  AND token = 'q6A04lIR+bNmG19dMOQd7M3Pls5gltSwzCsv6nZzJ0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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