SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '569bb050cefa0af2aedfcc99444a1deec5a10058129bed1af340b2e94dfc1340' 
  AND token = 'fUyNMGAtMuarODY3pGd1vIrHR5h+wzse6/h1uE1vgUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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