SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e835eec9291013895c8e4567659de90030446ddda81560fdc55d4c550f3d4ae' 
  AND token = 'D070lIUPTcehk7C2iQjlOvJLpNl/NvnL+QoFVUPVKQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}