SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af757ef32d2c6cfc76758062c0260851bb1024cbb95efcf7f4ccba6c69a216f' 
  AND token = 'UqKFSRZ5AFEOv0PsruVduH7/vNKQAzWyrk4QXFcANbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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