SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '67689bf359530f3792779756fb806628b1c649a06d78dd5643a07dd786decf84' 
  AND token = 'lZ2t6oXV/Y1k5Pvy6Aix/D3LVPvMx+Vi+Q4pnrBoljo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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