SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e03d97545810d3255a09be602a56062072e1745d183cf2bd2a28986554cdf6f' 
  AND token = 'Cn9/gXjwRfGSaBDfE7St/XgjvpJbamqtKZopAS1eU9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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