SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3472ff7d5e3bc951ab40f1e811e32b2bf86f3e5330026527fa0d4618a75c2c8' 
  AND token = 'FQB8UPPHLRWhzQjO4lOdlkhFGMEJJtYlMIVDe1tgGKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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