SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa039dad6365703dd3a8c8e2207f359a6035f3790ebdb07342085b42e0aac0a8' 
  AND token = 'eHTT4kmYNrufQx03wBU1a8OEq7ZiqaTNyUVihSIVeGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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