SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40301aecda9f5227aa70f849d6b984a7ad02356e0065dd523cc07514a0d65f32' 
  AND token = '6DP1QfxjGkqirZBHVNbUuYP9pNwOcrRhAsXGFj6IIWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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