Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f6126fffecc59d45b155e822cb151ec68d7e1dea320d514d64dcd7e7091a39c' 
  AND token = 'hUGAc9tkui8nuKzeh58f7FBoT0PGFdlVGFgbfaqJjXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}