SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1f7211d672cbce158c7c2ff8e47a7455353aec429bd03551d9b15c95dc3b571' 
  AND token = 'zJyhxElQ9D/9pubjZQSyIk76mPEgLbvqUCGowvVsua0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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