SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba96a5f7b05cd9298f1d091830dc9d51632b4a52a538151c44bb1eca5147841a' 
  AND token = 'uKT6ZhmTh4bOY3ONXnsZZbkCMdG1DbhqHqNqCyu2SR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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