SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1576817b3a14581df5fdbe9c3dfa406636a6bc85700089bd0dcaa431e325435b' 
  AND token = 'PNPOAqAjO6lPzShef/B9JmpaFRMloD+dtsalbYADL0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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