SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbbb0f5563df3464a2ec07d6a33fed0e2b128ead9e92f9b0fb5904cbf10777f4' 
  AND token = 'uFEi7BQCFXfgFWDVAYAehaI0VNd2UcaOnhmcqNnkhhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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