SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83af83ca091fd493a6926eec967aa2b8831c5748d3d7d35376bcf4e801fa0e27' 
  AND token = 'IAkJVFSQpbNn2Z7945rYul8ho3nxhkhwTCnjZXby8og=' 
  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"
    }
  }
}