SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a90b9e370802aaaf97fb7cba3d8a209c0e57e03154d0aa8d49294c8b8b1480a' 
  AND token = 'GXoj7M1AmGR5FNH519XxSfFpl8FkMCVetu+5mqZH/Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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