SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d73fb661dc308001ecb8e1e675c1dba23d6ee456363c206f67c2f89389a9c47' 
  AND token = 'MO+M6vZjV9nNtsqw3U/c87+ApdiVKTkp8ZEgN50G8QE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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