SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '689fd258e0ff44d24ca53119aa75fcecb85ce1d9f103e59ae215253310bf1f2c' 
  AND token = 'vY2zUQL4NoDgwoBVzE2TUvf4IRRTNOiENxdrgVpZ1zA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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