SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d508221bfa5a1e3d126d6867bf841d8223e392f1ed9d8ee16a892367eb0f6d3' 
  AND token = 'IzdZL84AHDCIqxgr5KIpK5BfzLvJVeU7xN5H+yeFEGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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