SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef62b7ff7254030c490943ccfe5d699dc50e777ce9bf190bd91fc60287083166' 
  AND token = '7RU2kd82tEQhxFTWR1SQTyPwFPNAuqDjH3Yi/x89+uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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