SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fae768194cf6e08e9d17d51bc471a65d860147f41358364c32ef524f668e210f' 
  AND token = 'ipA1KqPBP/dNw1auUTFVvag5NnVfeMvPxcZhc8nMFnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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