SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a989016309983b93b9996b18af0f43fa70b9caf8eea1cdc011e479f6fa31652' 
  AND token = 'mnWxglQ5U0L4q69fl+US0ONycS0jnNU348Lq7maT8uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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