SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35a05e63a993a12f6ae6306a05fc7a4bb4888999e1a7b377c94a2c242bbac45d' 
  AND token = 'vFL+1zfYpejXfU1KoHeHCz8Av66mT8VrB2+zyF/OFQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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