SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2aff20964511b1be6cad3f23d1400e4234899dcf48ffea762e938f86e5d95a9' 
  AND token = 'Cv7Qmqcbh+EFjozcTi6XTzS3RVrLw8XzNHRHims70LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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