SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cabec299e69a666f322019084808e9023286bf49e7b8fa7129db7c76f28425f6' 
  AND token = 'FVT7EI2xJnRRlGiM4wDdZ65ej/bAKnjLnFCjRSAhtZw=' 
  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"
    }
  }
}