SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd76011daca3254f1d9035f959e0770281231bb9e2c066427abc38cfd37c8880e' 
  AND token = 'QJORKPVw4dBc6uLFkkJgpcw6Zt1mwJdUxSOZh0PKvqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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