SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f83731d902f512a66ce2da34ac5e0f2af2b60c0e11fc61375c4dd9110b4f2ef2' 
  AND token = 'CFsyA8usKxt3AIVY0ameZ/tSTLfYj6OveV9spbPb20g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}