SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ac2a0d61a5c0c5ee136c68257e2ca136accb58f4942752ec30e989f139f3757' 
  AND token = 'l2JI4L9tiDfotJIfp0fJA9kp1Hus2t/wMNV3es47iD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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