SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca3286eddbdea8e5241ff727ef9d10aca09ace9204f04385c0bb1088a5308325' 
  AND token = 'PkYEwDDleozZk2vh6eyibVuTHdJ7FF9Zo1WdED31Sx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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