SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c97b7dee462365f22325e2c0cd74e0a73b71851c43694bdd4b8cb0370fffbe74' 
  AND token = 'nL/6f8g3HDMYrT0uOM8inq+5tn/oIE6l2l1mTRwyzi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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