SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69503f3abef2872bfdb4522fd13c780d80d704fa8d133bcd508eb6cf6edcb990' 
  AND token = 'ACXTix8U87VOfjPrnxD6gme35BHTXhU1A3dU8Eqvolg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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