SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdfbfda8d45c06311c50b9e8c6ce0795bb221be64423be25fdeea5d41b47bf0c' 
  AND token = 't/EzEJjuM7g1ldE2ZxR/JWLhjh/WcvEUD84jaNN/BhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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