SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb00d16c51a57f799106805de0136bdc619b0716c4c5413a118b23bdd6d270ef' 
  AND token = 'bjI2gPYEWvZQsLoPiyg8cRkDtPizltAwIohqfDpO5pU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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