SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '643ad239f6d7a6ff015f2ee4a2f092d37a0cdeaa2c143d7696cc796e527590d2' 
  AND token = 'nIZeaIG8Nvh0Qa1FZMOVHvh/xYGMJqzocn3HgpOBJ98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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