SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fea06464b77a91bdfd285453c5db54371b6bdd6bcbf1503dd868faaf5acbd0bc' 
  AND token = 'zYsnNvNoHXntz2qmE8ECAe84Ra9NrAod5wn4PDPHAhU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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