SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0911681368af0f00b161fe465737d549d49f821ec509a9023715c7243dc70e1' 
  AND token = '4JIVfJmd/jXWK5d335IISrJmmVWuUULZDNVPwMHZ2Vo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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