SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a36b546c61b67d046e0deff52f2816f8d69d5aaf152e82f5ecdc167c3d52793' 
  AND token = 'XAkhkzREJkRfhYRCrT8v3ARim4LZQwka1+Df+l0DCyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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