SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61f2c0025913bf6dea619ff619a02835f58120bf03ac90073953cc21dc1e75ff' 
  AND token = 'H6PlXabRo29iDOI/U2GDxrbY3lT8x5+3gqtCzm96n34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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