SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0789070a8f50e6295321aa86aa6c7af1a7e2a023d824dad97d2426ca58bd16cf' 
  AND token = 'Mgyai+oV+wKcwpZroz89e7OvEdHMJzsZzbA7hpSKk1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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