SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '897ba42398bb6baf200bb228850302c653ade9d9c5ef7b35d2e4b650559e15e6' 
  AND token = 'GBVrzS5vkXICuwKYMzzJs5yEkIpzuWVCzYdhfkAeJTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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