SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01e35ba9e46554fa75f56960c5253fcd692258efe3f6bd4d1f4eafec25cffd09' 
  AND token = 'X2jtuJV0b3HVYrMtRO6BX0F0ixAavVIiMKNggimMlOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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