SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f639133849c184cc110ec5d82b7a147559b01ed407b28a2eba69bb5181216b33' 
  AND token = 'GXZoqpV51QrRCsrfOPytGOCm+W3kgzep/0Sx/K+YBPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}