SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '531fdbae9bb55aabf7d4d2b46667adc15a2f453ed6190475503312604cec560b' 
  AND token = 'ZNaWmZAo7fFNrgC7jqXZ0PicbYfCUx/YQQAt2l6G1Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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