SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43226dcfe15ff30daddf5b6bc9349cd13eee81bb2962785beea7cc9081d24bdd' 
  AND token = 'lV9sfxt92mIxJWWaApCzQpSyB+fGBszwAEXh4+rcheo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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