SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f254c7b49ced09d9d2f1b2ba2c20edd5c73e4072f61a58836ab2dbee9cb15d59' 
  AND token = 'kvPGbS+CiQC+VkoAaYLlu5apYHqG/0u9bESORRv/LXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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