SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd25c94e0ae615b9134c8819b7b5b0502a25b66eb733af583cdf63298607f0d69' 
  AND token = 'khxzDFKHP+jxnLkiiaSGwVAbYdGpJd436LzPKEVo6Bk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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