SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e3f1e943d717cdec882e225eff40fd4719d9b9fafd224df32d584ea2e4035bb' 
  AND token = 'A05vrSB0g0/R6nmyYVjGWrAe0BA9xl3c4di+EYX0VQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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