SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd6279b5967f0a9b8bbd763199ea025339f52d418e6e7439cf3517342414c74e' 
  AND token = 'OE2ds5Jv1PHxG7QDjZcSMsveqW/Vnlni5SjuhKhNuF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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