SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '268a0566dfe66ef7ebfe43cec965e181293b87cb4d0edff46d09cc495fc7200e' 
  AND token = 'IIjTBFfHyrtii08itBAzn+S/zRCbeZ0aBMbdTj7h1m8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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