SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73202ca10c37cfbb7ef35b4182f676f4e38089d900d87778c2cd7451d7bb26bf' 
  AND token = 'RZsVczQj92REgm6wryTQ/sNhjnzXqG5+JKCCos5H3lE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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