SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f82703b4cd23ca447fa724db62bcaa34ce30c2e7621098acda40a7e2c28f28c' 
  AND token = 'HjWv6pgD5QCcOb2nIEYvj0lvXQchYeHsJcq1DhniVuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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