SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62cd76725e21151a4ccb864ed184a764fd6b96a77c12c7f8fe370f8dd0d344b0' 
  AND token = 'lvfv5Bfm0NimHM059a1kEhA59EvS7hYlGHMFSzPE0EE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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