SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d834f78bd2dd602a2c90d06dc981289c07479f61eba19c7a3e6d12b76926ae5' 
  AND token = 'UkeZzig7lMyF+JaSzsDJUAb7GmQTJ6ap6CJIxS2KKRM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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