SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c6579f46fa5a429985f2ba41384346e309641b8f811aea7f8bf75200524134c' 
  AND token = 'YKAkRGBpfWuEcY7PRVaU/0S2oNv8i3+vOCxih8w9SyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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