SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34d82297e3c0e98b37a571b8e5224462e419cad30136ea532b5f25e0c7698a0b' 
  AND token = '+vPtEzsrbiJ4syA+lrbPRAuY0EIcYr2Rc4i0m7a410s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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