SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97d10437dea1ac2fd343ffea1c58775a183fded274246eccd21c1507a3d113eb' 
  AND token = '7k4cZ5KNxVJKvlHL8OovTWYlZwNoXN1OmJov2rASr9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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