SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '678b7e1f42d6f95bc6acad067db7fc93dfe5a1943988cf651bf3a80135819181' 
  AND token = 'jsOGNh3aZA+OowkfS4h3tfntDvBYfMphz20LlYMpswA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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