SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8cdf0fe58ea69b5cd2d755cd41b2c86234d1722967fb81ae2cc074f45bd9d30a' 
  AND token = 'B7q0qCW+/dWOtDpKiO19Cq3ikFvNhBitzxPxrQkC/gM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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