SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2892545720b49efccaf504c44158e49001eecb018a362edaaead766bcd402dc' 
  AND token = '7OdMNf+dbEJ2RN6gv7up+JKLfMRsJ3WQKK2eTEX/JJ4=' 
  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"
    }
  }
}