SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49fc57a8318f85cd1194bbe5ae8e4665ce2a66e798f11ecf88017640967ac357' 
  AND token = 'Y75p3u9DoMiek03bCeRD5eNp04bi/kCw4FoTzi+T0S4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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