SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e189d97f190fb8ad959b61fd6a8376bf0a1f307c20bf6c4f5e11b652e7145a81' 
  AND token = 'iNO4QjuLaVPtcQ+nFVRgFAluwtQs5Iev3UIZK2rvvOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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