SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '925f737f8afb72b11f400cc57cd5861991c7814bca9c6bde35022e3091c03d2c' 
  AND token = 'mQP6BZEG7YW8nV2OtVpwEL8Nzxpv5a2ouW1xFeDbCNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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