SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b73a6862a722716bb6a1ac91f8fa2bff2fe382693636e275c33aa2335cbaf3b' 
  AND token = 't6XH0Dgr6Kajzvrjv1vK1TTL36/3Tr9gNKL6sIEGmos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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