SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f629fb6bfb5d863d8818c99ea704d3c6c5a9e4bae6704bffae29683347adcefd' 
  AND token = 'm2PsGmCCLnXy2xMQMqxv9DZ/VPRhGJesBm2vp1UhRbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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