SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8006e6d33d72bf28985f4604cf2b71c0a6f3d6654d71fa34206744d52e538fbd' 
  AND token = 'TBHTfXVmyyLaR7q1aU6Ib0iiKY7dEIiuvNWgpgiqg/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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