SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96c5349f8332d9fe93962a7f087562d36206c893f41b18af39d872f27048aab5' 
  AND token = 'T0KQmM8zLN+Bd1cpm2oLeKuSVE9qo/bZDyS37jxS5wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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