SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5927cbf8558d87c2a4f56aec64198db0bce64d2d76b2bded82c1fdfba973ceb1' 
  AND token = 'ZF1CaOJh6v1nZvQ/VHNGzmrNuQqYvOWqHTMAIWFpx28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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