SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f100c3433737469c095a03c8df0bfb95eff0bc4b1a822cde254be69be7445b2' 
  AND token = 'Ajy5ALsDdxp7YjgGtQQZiYrwRIVvF6bgb0KeBRekDHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}