SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a084163bc464c76e53d65125869603818372209100b2e25f2906eeda378d202d' 
  AND token = 'RNFkNLR1FFy9GgMD0Tqphi/UyixMduaD8WTfTJTNRZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}