SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26b692ee0a8f4d493138a35fe0e56eadcda0a2fe11e16d2508bcdde572fcef36' 
  AND token = 'CabvOcxdEiOc2tKOVyRBJYUzQPMmWsJcP3x8dY1wV7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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