SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77e9458bb0a520284fd09e4f1fde4a2d883712c710d54857d2b529e8800ada15' 
  AND token = 'sf+9ADrqrmUbh8rsycSPHYaHG56tRqx2wrAPrEtBx1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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